Plants, being sessile organisms, have developed sophisticated defense strategies to combat various biotic and abiotic stresses. This chapter focuses on elicitor-induced secondary metabolism that serves as a crucial mechanism for enhancing plant resilience and adaptability. Elicitors are the molecules derived from biotic (e.g., pathogens, MAMPs, DAMPs) or abiotic (e.g., UV light, heavy metals) sources that trigger complex signaling cascades in plants. These signaling cascades include calcium influx, Reactive Oxygen Species (ROS) production, and Mitogen-Activated Protein Kinase (MAPK) pathways, which regulate the biosynthesis of secondary metabolites such as phenolics, terpenoids, and alkaloids. These metabolites play key roles in strengthening plant defenses, such as pathogen resistance, herbivore deterrence, and tolerance to various environmental stresses. The chapter explores the molecular mechanisms of elicitor perception, transduction, and response, emphasizing the roles of transcription factors (e.g., WRKY, MYB, and bZIP) and hormonal signaling (jasmonic acid, salicylic acid, and ethylene). It also highlights the integration of epigenetic modifications, such as DNA methylation and histone modifications, in fine-tuning defensive responses. Advances in transcriptomics, metabolomics, and gene-editing technologies, such as CRISPR-Cas9, are discussed as transformative tools to unravel these processes. Beyond the molecular framework, the chapter discusses the practical implications of elicitor-induced secondary metabolism for sustainable agriculture and biotechnology. Applications include the development of stress-resilient crops and the production of bioactive compounds for pharmaceuticals and bio-pesticides. By bridging fundamental insights with applied innovations, this chapter offers a comprehensive perspective on harnessing elicitor-mediated pathways to address agricultural and environmental challenges.